1. Field
Embodiments relate to a dicing die bonding film, a semiconductor wafer, and a semiconductor device.
2. Description of the Related Art
In a semiconductor manufacturing process, a circuit designed wafer may be back-ground and laminated with a dicing tape or dicing die bonding tape, followed by cutting the wafer into small chips through dicing. Then, the separate chips may be bonded to a substrate, e.g., a PCB or lead frame substrate, through a bonding process. For example, the semiconductor manufacture process may include a back grinding process (in which the wafer is thinned), a mounting process (in which a dicing tape or dicing die bonding tape is mounted on a rear side of the wafer), a dicing process (in which the mounted wafer is cut into, e.g., a uniform size of, pieces), a UV irradiation process (in which UV light is irradiated to the tape), a pick-up process (in which each chip is picked up), and a die bonding process (in which the chip is bonded to a support member). The dicing tape may be attached to the rear side of the wafer in the mounting process, thereby preventing vibration of the wafer, securely supporting the wafer, and reducing or preventing formation of cracks on the chips or on lateral sides of the chips due to a blade used in the dicing process. Further, a dicing film may be expanded in the die bonding process to facilitate pick-up.
The dicing tape may be a pressure-sensitive adhesive dicing tape or a UV-curable dicing tape. The UV-curable dicing tape may be used to make a wafer thin and to pick up various sizes of chips.
When dicing is completed, UV light may be irradiated from a back side of the UV-curable dicing tape to cure an adhesive layer and to decrease interfacial peel strength with respect to the wafer, thereby facilitating a pick-up process of separate chips. In order to package the separate chips after dicing so that electric signals may be applied to the chips, a process of bonding the chips to a substrate, e.g., a PCB or lead frame substrate, may be used. For example, a liquid epoxy resin may be placed onto the substrate, and the separate chips may be attached thereto to be bonded to the substrate. This two-stage process, in which the dicing process uses the dicing tape and the die bonding process uses the liquid epoxy resin, may incur undesirable costs and poor yield.
Methods utilizing a dicing die bonding film may be used. In these methods, an epoxy film may be placed on a film provided as a dicing tape, and pick-up may be conducted between a pressure-sensitive adhesive of the dicing tape and the epoxy film, thereby combining the two-stage process into a single stage process. In this regard, these methods may be advantageous in terms of time and yield.
As multi-layer structure and high integration are realized in a semiconductor process, a wafer may become thinner. When thin wafer chips are picked up, the wafer may bend and the chips may be damaged by minor external impact. Thus, it may be important for equipment adjustment parameters for pick-up of pick-up/die bonding equipment to be in a lower level than in pick-up of an existing thick-film wafer. The equipment adjustment parameters for pick-up of the pick-up/die bonding equipment may include an expanding extent, the number of pins, a pin elevation height, a pin elevation rate, decompression pressure, the kind of collet, and the like. For example, a pin elevation height and a pin elevation rate may be key parameters in adjustment of pick-up, but these two factors may be adjusted within substantially limited ranges for thin chips. When a pin elevation height increases to facilitate pick-up, a thin chip may crack or may be damaged, causing reliability deterioration after packaging. Thus, in order to facilitate pick-up of a thin wafer (having a thickness of 80 μm or less), a dicing tape should have remarkably low peel strength with respect to the wafer after UV curing, as compared with a dicing tape used to pick up a thicker wafer.
For this reason, a UV-curable dicing tape may be considered. However, the UV-curable dicing tape may be unfavorable in terms of long processing time and high costs for a UV process. In order to reduce the processing time and costs, a pressure-sensitive adhesive dicing tape may be considered. However, a pressure-sensitive adhesive dicing tape may cause detachment of a ring frame or creeping of wafer chips during a dicing process when the dicing tape has low adhesive strength to the ring frame.